軽金属
Online ISSN : 1880-8018
Print ISSN : 0451-5994
ISSN-L : 0451-5994
検索
詳細検索
OR
閲覧
検索
60 巻, 4 号
選択された号の論文の8件中1～8を表示しています
すべての抄録を表示する
    • |<
    • <
    • 1
    • >
    • >|
研究論文
  • Al–Fe–Si三元系合金のミクロ偏析とFe系化合物の晶出モデル
    森下 誠, 石田 斉, 吉田 誠
    原稿種別: 研究論文
    2010 年 60 巻 4 号 p. 157-163
    発行日: 2010/04/30
    公開日: 2010/05/30
    DOIhttps://doi.org/10.2464/jilm.60.157
    ジャーナル フリー
    抄録を表示する抄録を非表示にする
    In order to develop high quality aluminum alloy products, modeling to predict a behavior of solute distribution in dendrite and precipitation within the inter-cell region quantitatively is important. However Scheil's and Brody-Flemings's equations can't find the precipitation behavior during solidification because a diffusion in liquid phase is not considered. Numerical analysis methods typified by “Phase Field” are more effective but a calculation time has not been enough short to apply industrial use, yet. Consequentially a mathematical model is developed based on the Matsumiya's calculus of finite differences for analyzing inter-cell microsegregation and precipition. Diffusion of solutes in both the solid and liquid is taken into consideration, and realistic mesh shape to calculate microsegregation is conducted for finite difference calculation at this Matsumiya's model. But the calculus hardly predict precipitation behavior, since liquid concentration shift by precipitation during solidification is not considered. Then we improved the model to estimate precipitation of intermetallic compounds by thermodynamics database in this work. Additionally evaluation method of microsegregation used by EPMA was developed. Consequently, we built a new segregation model, which could predict both the microsegregation and the kinds and amount of intermetallic compounds.
    抄録全体を表示
    PDF形式でダウンロード (2617K)
  • 過剰にMgを含むAl–Mg2Si合金の時効析出過程に対するCuまたはAg添加の影響
    中村 純也, 松田 健二, 降籏 あづさ, 丹羽 健史, 川畑 常眞, 池野 進
    原稿種別: 研究論文
    2010 年 60 巻 4 号 p. 164-169
    発行日: 2010/04/30
    公開日: 2010/05/30
    DOIhttps://doi.org/10.2464/jilm.60.164
    ジャーナル フリー
    抄録を表示する抄録を非表示にする
    The precipitates in Cu or Ag added excess Mg type Al–Mg–Si (ex.Mg) alloys at over aged condition have been observed by high resolution transmission electron microscope (HRTEM), classified according to characteristic of their HRTEM images, and compared with those in the ex.Mg alloy to understand the effect of Cu and Ag addition on their precipitation sequence. HRTEM images obtained for cross sections of precipitates in the Ag added ex.Mg (ex.Mg–Ag) alloy have been classified into five types according to the periodicity of bright dots in them; the random-type, parallelogram-type precipitates, parallelogram-type (60°) precipitate having interior angle about 60°, β″ and β′-phases. The β′-phase in this alloy was predominant in later stage of aging. HRTEM images obtained for cross sections of precipitates in the Cu added ex.Mg (ex.Mg–Cu) alloy have been also classified into the same five types of precipitates as those in ex.Mg–Ag alloy. In addition, the Q′ phase has been also observed in this alloy and it was predominant in later stage of aging. Different shape of precipitate has been also confirmed in both alloys. It is the lath shaped precipitate having elongated cross section, and it has been regarded as the elongated type precipitate. This elongated type precipitate in ex.Mg–Cu alloy was predominant in later stage of aging, although there were a few in ex.Mg–Ag alloy.
    抄録全体を表示
    PDF形式でダウンロード (6880K)
  • カルシア系鋳型を用いて鋳造した生体用β型チタン合金の寸法精度の改善
    堤 晴美, 新家 光雄, 赤堀 俊和, 仲井 正昭, 竹内 力, 桂 成基
    原稿種別: 研究論文
    2010 年 60 巻 4 号 p. 170-176
    発行日: 2010/04/30
    公開日: 2010/05/30
    DOIhttps://doi.org/10.2464/jilm.60.170
    ジャーナル フリー
    抄録を表示する抄録を非表示にする
    The applicability of a calcia mold to casting a β-type titanium alloy, Ti–29Nb–13Ta–4.6Zr (TNTZ), was evaluated with focusing on the dimensional accuracy of the casting in this study. Pure zirconium particles were added to a calcia mold to take advantage of the expansion of oxidized zirconium during the baking process in order to compensate for the solidification shrinkage of TNTZ. The morphological characteristics of the casting surface, such as the roughness and dimensional accuracy, of the cast TNTZ were investigated. The dilation ratio of the calcia mold is found to increase with increasing the number of pure zirconium particles. The addition of 12 mass% or 14 mass% pure zirconium particles compensates for not only the solidification of TNTZ but also the occurrence of shrinkage of the calcia mold. In addition, the formation of a surface reaction layer in TNTZ is restrained to a larger extent by casting into a calcia mold than into a magnesia mold, which is the conventional investment mold for titanium casting. Furthermore, the volume fraction and number of casting defects are also restrained to a larger extent by casting into a calcia mold than into a magnesia mold. The results of this study should lead to enhancements in the creation of cast TNTZ for dental products.
    抄録全体を表示
    PDF形式でダウンロード (3612K)
  • カルシア系鋳型を用いて鋳造した生体用β型チタン合金の機械的性質
    堤 晴美, 新家 光雄, 赤堀 俊和, 仲井 正昭, 竹内 力, 桂 成基
    原稿種別: 研究論文
    2010 年 60 巻 4 号 p. 177-182
    発行日: 2010/04/30
    公開日: 2010/05/30
    DOIhttps://doi.org/10.2464/jilm.60.177
    ジャーナル フリー
    抄録を表示する抄録を非表示にする
    A calcia mold, which is stable at high temperatures for dental precision casting of β-type titanium alloys such as Ti–29mass%Nb–13mass%Ta–4.6mass%Zr alloy (TNTZ) with high melting point, has been developed. The applicability of the calcia mold to casting TNTZ was evaluated with focusing on the mechanical properties of the casting in this study. The molten TNTZ was cast into the calcia mold of which dimensional accuracy was controlled by adding pure zirconium particles. The tensile and fatigue properties of TNTZ cast into the calcia mold were examined with comparing those of TNTZ cast into the magnesia mold, which is the conventional one for casting titanium alloys. The tensile properties of TNTZ cast into the calcia and the magnesia molds are not markedly different. The fatigue strength of TNTZ cast into the calcia mold in the low- and high-cycle fatigue life regions is slightly higher than that of TNTZ cast into the magnesia mold. Therefore, the calcia mold is expected to be applicable to the dental precision casting of TNTZ.
    抄録全体を表示
    PDF形式でダウンロード (2442K)
  • Al–0.6%Mg–1.0%Si合金のベークハード挙動に及ぼす予ひずみ付与および予備時効処理の複合効果
    増田 哲也, 高木 康夫, 櫻井 健夫, 廣澤 渉一
    原稿種別: 研究論文
    2010 年 60 巻 4 号 p. 183-189
    発行日: 2010/04/30
    公開日: 2010/05/30
    DOIhttps://doi.org/10.2464/jilm.60.183
    ジャーナル フリー
    抄録を表示する抄録を非表示にする
    The effect of pre-straining in combination with pre-aging on bake-hardening behavior of an Al–0.6 mass%Mg–1.0 mass%Si alloy was investigated by means of Vickers hardness test, electrical conductivity measurement, differential scanning calorimetry (DSC) and transmission electron microscopy (TEM). Hardness change and DSC analysis revealed that only 3% pre-strain suppresses the formation of clusters; i.e. cluster (1), during single aging below 343 K. On the other hand, by combining with pre-aging at 343 K, pre-straining was found to improve bake-hardening response during final aging at 443 K. TEM observation confirmed that the improvement of bake-hardening response by pre-straining is mainly due to the enhanced precipitation of β″ phase in the matrix. These results are explained by the consideration that dislocations induced by pre-straining reduce the concentration of quenched-in excess vacancies, resulting in both the suppressed clustering of solute atoms during pre-aging and the accelerated precipitation of the β″ phase from more supersaturated solute atoms in final aging.
    抄録全体を表示
    PDF形式でダウンロード (2270K)
研究ノート
講演
連載講座
    • |<
    • <
    • 1
    • >
    • >|
feedback
 Top